The field of this invention is blowout preventers for use on a well casing or well pipe.
Heretofore, blowout preventers have been constructed with ram seals which have been removable by moving the bonnets or heads of the blowout preventer to an open position so as to expose the ram seals for removal and replacement from the outside or externally of the well casing. In recent years, blowout preventers have been used on offshore wells, usually in the water and usually at depths of three hundred feet or more. This requires one or more deep sea divers to go down in the water and effect the opening of the blowout preventers, removal of the old ram seals and replacement with new ram seals. In some cases, the entire blowout preventer must be pulled out of the water. In any event, such past procedures usually have required about 24 hours or more, which is expensive down-time on the well.